Apparatus for thermal treatment of metal parts by electric induction heating

ABSTRACT

The present invention relates to an apparatus for heat treating metallic work pieces and local electric tempering of in particular cross members of universal joints, the apparatus comprising an inductor effect electric induction heating of the work-pieces. According to the present invention, the inductor of such an apparatus includes a pair of serially connected sections, each section including at least two electric conductors lying in a plane and connected for electric current to flow therealong in opposite directions, the plane of the conductors of one section intersecting the plane of the other section at substantially right angles.

United States Patent 1 3,696,225 Kalner et al. [451 Oct. 3, 1972 [5 APPARATUS FOR THERMAL [56] References Cited TREATMENT OF METAL PARTS BY ELECTRIC INDUCTION HEATING UNITED STATES PATENTS [72] Inventors. veniamin Davidovich Kalner, 3,005,894 10/ 1961 Carbo et al. ..2l9/10.69 2,419,116 4/1947 Cassen et al. ..219/l0.61 X Anatoly Georglevich Orlovsky, Gri- 3,121,780 2/1964 Mucha etal ..219/l0.43 X gory Arkadievich Ostrovsky, Alex- 3 301 991 1 1967 G I a] 219 10 79 x andr Moiseevich Ryskind, Viktor else et Nikolaevich Semen, Analoly FOREIGN PATENTS OR APPLICATIONS Loginovich Stepin, Mikhail Andreevich sumv Konstantin 941,245 7/1948 France ..219/l0.59 harovich Shepelyakovsky, Isaak Nau I khimovich Shklyarov, all of Mosf' Staubly cow, USSR jsszstant lilrflarlnmerzlilugh .i'sleger & S b ld W tt0rney 0 man, ascoc owning ee 0 [73] Assignee: Moskovisky dvazhdy ordena Lenina i ordena Trudovogo Krasnogo Zna- [57] ABSTRACT meni Avtomabilny Zavod imeni LA. Likhacheva, Moscow, U.S.S.R. The present invention relates to an apparatus for heat [22] Flled' June 1970 treating metallic work pieces and local electric tem- [21] Appl. No.: 45,005 pering of in particular cross members of universal joints, the apparatus comprising an inductor effect electric induction heating of the work-pieces. [30] Forelgn Application Pnomy Data According to the present invention, the inductor of June 17, 1969 U.S.S.R. 1336662 such an apparatus includes a pair of serially connected sections, each section including at least two electric [52] US. 11. ..219/10.79, 219/ 10.57, 219/ 10.59, conductors lying in a plane and connected for electric 219/ 10.69 current to flow therealong in opposite directions, the [51] Int. Cl. ..H05b 69/06 plane of the conductors of one section intersecting the [58] Field of Search..219/10.79, 10.61, 10.43, 10.57,

plane of the other section at substantially right angles.

4 Claims, 3 Drawing Figures PATENTED UN 3 i972 SHEET 1 0F 2 Q QMV M PATENTEDUCT 3 I972 SHEET 2 [1F 2 APPARATUS FOR THERMAL TREATMENT OF METAL PARTS BY ELECTRIC INDUCTION HEATING The present invention relates to an apparatus for heat treating metallic work pieces in particular cross members of universal joints, effected by electric induction heating.

There is a known inductor structure for local heating of articles, including a rectangular frame of electric conductors. When a cross member is positioned within such inductor, a pair of opposite comer areas of the cross member can be locally heated to a required temperature, which is essential for rendering the cross member sufficiently hard.

However, this known inductor structure has a serious drawback, namely: in order to effect tempering of the other pair of the opposite corner areas of the same cross member, the latter has to be either re-heated in another inductor structure, turned through 90 in relation to the first inductor structure, or else the cross member has to be turned through 90 itself for re-heating in the same inductor structure.

Should two different inductor structures be used for tempering the two pairs of the opposite comer areas of a cross member, it might lead to non-uniform tempering of the corner areas, and in order to prevent this eventuality, complicated additional equipment may be required.

Rotating each cross member through 90 for re-heating brings about the necessity of using complicated mechanical devices.

Consequently, the said drawback aggravates the problem of introducing automation into the process of thermal treatment of cross members of universal joints.

It is an object of the present invention to provide for an apparatus for local electric tempering of cross members of universal joints comprising a single inductor, which provides uniform tempering of all the four corner areas of each cross member, without the necessity of turning the cross members through 90 for the purpose and without the necessity of two separate inductors.

It is yet another object of the present invention to create an inductor for the above specified apparatus, which facilitates automation of the process of heat treatment of metallic workpieces, e.g., cross members of universal joints.

Other advantages of the present invention will be made apparent in the detailed description of a preferred embodiment thereof, given hereinbelow. An apparatus for local tempering of cross members of universal joints, constructed in accordance with the present invention, comprises an electric inductor having a pair of serially connected sections, each said section including at least two electric conductors lying in a plane, said two conductors being connected for electric current to flow therealong in opposite directions, plane of said at least two conductors of one section intersecting the plane of said at least two conductors of the other section at substantially right angles.

In accordance with the present invention, there is created an inductor structure for an above specified apparatus, which provides for obtaining a desired quality of tempered cross members, and, at the same time, facilitates the task of introducing automation into the process of thermal treatment of such cross members.

An apparatus incorporating an inductor, constructed in accordance with the present invention, is capable of effecting local tempering of all the four corner areas of a cross member, with the cross member being positioned in the apparatus but once, on account of the said inductor comprising a pair of sections, each said section including an electric conductor, wherein electric current flows in one direction, and another conductor, wherein electric current flows in the opposite direction, the two conductors lying in one and the same plane with the axis of symmetry of the cross member. Each one of said pair of sections is capable of heating a respective one of the two pairs of the opposite corner areas of a cross member.

In accordance with the present invention, the respective planes of said pair of sections intersect each other substantially at right angles, whereby when a cross member is transferred from one of said pair of sections, where one pair of the opposite corner areas thereof has been treated, into the other one of said pair of sections, the other pair of the opposite comer areas is treated.

The present invention will be better understood from the following detailed description of an embodiment thereof, with reference to the accompanying drawings, wherein:

FIG. 1 shows a schematic plan view of a tempering apparatus, incorporating an inductor embodying the present invention;

FIG. 2 shows a device for retaining cross members on the rotary work table of an apparatus of FIG. 1;

FIG. 3 shows schematically an inductor embodying the invention.

Referring now in particular to the appended drawings, a tempering apparatus, constructed in accordance with the present invention, comprises an electrical inductor 1 (FIG. 1) connected to a highfrequency step-down transformer 2, a cooling-agent spraying device 3, a rotary work table 4 carrying a plurality of angularly spaced devices 5 adapted to carry cross members of universal joints, or crosses 6 and retain these crosses in a desired position relative to the inductor 1.

Each device 5 for retaining thereon the crosses 6 includes a pair of bushings 7 (FIG. 2) mounted on the rotary table 4 and a pair of knife edges 8 carried by a horizontal bar 9 which, in turn, is mounted on a vertical support 10. The vertical dimension, or the thickness of the horizontal bars 9, as well as the dimensions of the vertical supports 10 in the areas which are positioned adjacent to the electric conductors of the inductor during a tempering operation, are preferably each smaller than the diameter of an arm of the cross 6. This is necessary to obviate the said members of the device 5 excessively heated; each time when a cross carried thereby is being heat treated.

The inductor 1 (Fig. 3) which is meant to effect heating of universal joint crosses for local tempering thereof is so constructed that in its left-hand section a pair of the opposite corner areas of the cross 6 is heated, i.e., the corner areas which are positioned adjacent to the electric conductors of the inductor l in the left-hand section thereof, while the other pair of the opposite corner areas of the same cross 6 is heated in the right-hand section of the inductor 1. According to a preferred embodiment of the present invention, the number of crosses simultaneously heated in each of the two sections of the inductor 1, respectively, is the same for both sections; this number may be either one, or more. Fl GS. 1 and 3 show the inductor l'wherein two crosses 6 are simultaneously treated in each one of the two sections of the inductor. The arrows in FIG. 3 indicate the instantaneous direction of the electric current through the electric conductors of the inductor 1,

In the operation of the herein disclosed apparatus, each successive rotation of the rotary work table 4 through an angular step equal to the angular spacing of the devices 5 about the table brings a successive device 5 with a pair of crosses 6 carried thereby into the lefthand section of the inductor 1. When the rotary step of the table 4 is completed, the inductor l is energized for effecting heating. When the heating is over, the cooling agent spraying device 3 is actuated, either immediately or after a brief pause, and the cooling agent, e,g., water, is directed from the nozzles of the device 3 onto the crosses 6.

Thereafter the rotary work table 4 with the devices 5 carried thereby is again driven'for the next successive rotary step equal to the angular specing of the devices 5 This step brings the pair of crosses which have been previously treated in the left-hand section of the inductor 1 into the right-hand section of the latter, whereas the left-hand section receives therein the next following pair of crosses 6 carried by the successive device 5.

Then the above described sequence of energization of the inductor l, heating, de-energization of the inductor I, pause (or none), actuation of the cooling agent spraying device 3 is repeated. After the next successive rotary step of the rotary work table 4 a pair of crosses 6 issues from the right-hand section of the inductor 1, carried by the respective device 5, which crosses have all the four corner areas of each of them uniformly tempered.

In the hereinabove described apparatus the combination of a two-section electrical inductor with a plurality of component carrying devices mounted on a rotary table provides for performing the entire heat treating operation without the necessity of removing the components for re-positioning thereof, whereby each rotary movement of the table 4 results in delivering either one or several steel crosses having all the four corner areas of each cross uniformly tempered.

What we claim is:

1. An apparatus for thermal treatment of metal workpieces by electric induction heating as .the workpieces pass thereby, comprising an electric inductor defining first and second longitudinally spaced heating zones through which the workpieces successively pass, each zone being provided with induction heating means which are electrically connected in series defining said inductor; each heating means comprising at least two longitudinally disposed conductors spaced apart in a plane and connected for current flow in opposite directions, the planes in which conductors of said first and second heating means are located intersecting substantially at right angles.

2. The heat-treating apparatus as in claim 1 wherein the two heating means are constituted by an integral conductor.

3. The heat-treating apparatus as in claim 1 wherein said two conductors of each heating means are substanl y'l fie ii z it-treating apparatus as in claim 1 further comprising a support structure for the workpieces, wherein the cross-sectional dimensions of the support structure are substantially less than those of the workpieces. 

1. An apparatus for thermal treatment of metal workpieces by electric induction heating as the workpieces pass thereby, comprising an electric inductor defining first and second longitudinally spaced heating zones through which the workpieces successively pass, each zone being provided with induction heating means which are electrically connected in series defining said inductor; each heating means comprising at least two longitudinally disposed conductors spaced apart in a plane and connected for current flow in opposite directions, the planes in which conductors of said first and second heating means are located intersecting substantially at right angles.
 2. The heat-treating apparatus as in claim 1 wherein the two heating means are constituted by an integral conductor.
 3. The heat-treating apparatus as in claim 1 wherein said two conductors of each heating means are substantially parallel.
 4. The heat-treating apparatus as in claim 1 further comprising a support structure for the workpieces, wherein the cross-sectional dimensions of the support structure are substantially less than those of the workpieces. 